Data on Lithium-7 Nuclear Magnetic Resonance spin-lattice relaxation times in several systems, including human platelets, have been compiled. The nucleous possesses the necessary nuclear magnetic resonance characteristics, such as sensitivity, to be a promising probe for biological systems. Binding to adenosine triphosphate (ATP) and displacement by calcium ion is mirrored by a significant change in the spin-lattice relaxation time of the lithium.